Brian Harradine, Australia's longest-serving independent senator, has been honoured at a state funeral in Hobart.

Mr Harradine, who died last week aged 79, represented Tasmania for 30 years and became known as the "father of the Senate".

Family, dignitaries, former colleagues and friends gathered at St Mary's Cathedral for a traditional Catholic service for the man who was a devout Christian.

Among the mourners were former prime minister John Howard and Tasmanian Premier Will Hodgman.

Archbishop of Hobart Julian Porteous paid tribute to Mr Harradine during his homily.

"Brian Harradine has gained respect as a man of high principle and integrity," the Archbishop said.

"He's seen by allies and by those opposed to him as a man who will not go down paths of expediency or compromise in order to achieve his ends.

"Brian leaves behind an extraordinary legacy of good.

"He never claimed the limelight, or sought to gain credit for what he achieved, he never wanted fuss. He would have probably thought today was a little over the top."

Son recalls humble, faithful father

In a written memorial, his son Bede described his father as a humble man and perfect gentleman, who remained faithful to family, friends, society and God to the end.

He recalled his dedication to "values and organisation" and the aims of the International Labor Organisation for people to live with freedom and dignity.

Brian leaves behind him an extraordinary legacy of good.

Archbishop of Hobart Julian Porteous

The tribute reads in part: "Dad always knew the limits of the public life. He himself once spoke whimsically of being a rooster one day, and ending up a feather duster the next.

"Over the years, many tried to stereotype and pigeon-hole my father. Yet Brian Harradine - the statesman in the tradition of Thomas More - was always deeper, his vision far broader than they could fathom."

Mr Harradine was expelled from the Labor Party in 1975 after accusing the party's national executive of having communist links.

He served as an independent senator for three decades, playing an instrumental role in the part sale of Telstra and Wik native title amendments.

Fierce negotiator for Tasmania

After the service, Mr Howard remembered Mr Harradine as a man who could be trusted and who was a fierce negotiator for Tasmania.

"He was a man of great integrity," the former prime minister said.

"He was at heart a Labor man; he didn't leave the Labor Party - the Labor Party left him."

"He agreed with me on some things and supported my government in a very effective way, but on other things we couldn't reach agreement, which is understandable because they were not things in his heart.

"But what I liked and respected in him always was his great integrity, and reliability and honesty."

Among those who have paid tribute are retired state MP Michael Polley, who knew Mr Harradine as a Labor member in the late 1960s.

Mr Polley says many in the party regretted expelling him.

"In the state here it led to us going into opposition for a long time," Mr Polley said.

"One of the biggest unions in the state has only re-affiliated in the last six or seven years as a result of that and it caused a lot of ructions within the party.

"He was very humble he would not have wanted this, but the state and the nation wanted to honour him in this way and I think it was fitting."

"Right through his career he stood up for the working man and trade union rights."